the old bridge of Mostar

Mostar in Bosnia was named after the bridge keepers (natively: mostari) who guarded the Stari Most ("Old Bridge") over the Neretva river.

You only need to look at what buildings are in the background to realise some of the ethnic tensions that have existed in Bosnia-Herzegovina which flared violently in the early 1990s and led to the infamous war.  The landmark footbridge was destroyed in the war on 9 November 1993 and rebuilt in 2004.

The caption on the postcard from the 1900s calls it the Römerbrücke or Roman bridge - actually it was completed in 1566. Probably the attention that resulted from its destruction and rebuilding has now made it one of Europe's most famous.

Description:
Hump-backed, 4 metres (13 ft 1 in) wide; 30 metres (98 ft 5 in) long, height 24 metres (78 ft 9 in).
Two fortified towers "protect" it: the Helebija tower on the northeast and the Tara tower on the southwest, called the bridge keepers (natively mostari).
The "arch" of the bridge was made of local stone known as tenelija. Instead of foundations, the bridge has abutments of limestone linked to wing walls along the waterside cliffs. Measuring from the summer water level of 40.05 m (131 ft 5 in), abutments are erected to a height of 6.53 metres (21 ft 5 in), from which the arch springs to its high point. The start of the arch is emphasized by a molding 0.32 metres (1 ft 1 in) in height. The rise of the 'arch' is 12.02 metres (39 ft 5 in).